Instrument for evaluating crease performance in flexible materials



United States Patent TLS. Cl. 356l56 3 Claims ABSTRACT OF THE DISCLOSURE The invention includes an apparatus and method for evaluating the sharpness of a crease in a material such as a fabric. A collirnated light source is used to cast a line image onto the inside of the crease and at an oblique angle thereto while the fabric is positioned on a tube, the reflected image is compared with a standard to evaluate crease performance.

The present invention relates generally to an improvement in material inspection and testing and more particularly to an apparatus and method for evaluating the sharpness of a crease in garments and coverings and materials associated therewith.

The present invention is adaptable to the evaluation of creases in any of the wide variety of materials associated with the garment, textile and paper industries. However, the present invention should prove most useful in testing, inspection and evaluation of garments and garment materials which have been processed to impart thereto, shape retaining characteristics. Although such characteristics have long been considered important, it has only been in recent years that materials and material processing have allowed a degree of success in providing these most desirable characteristics.

Today, a rather wide range of products are available which are known as wash and wear products. These include, for example, such things as shirts, trousers, jackets, tablecloths and raincoats. The purpose of the wash and wear concept is to provide a product which will not have puckering along the seams, which will resist wrinkling and which will retain sharp uniform creases. For example, a wash and wear garment ideally would be initially pressed at some point in its manufacture, and never repressed thereafter.

There are many different approaches to the imparting of wash and wear characteristics to materials. The performance of a particular material will depend on its processing as well as the constituent make-up of the material involved. As might be expected, all of the various combinations of materials and processing methods result in products which will perform in somewhat diflerent ways. That is, there is a variance in the ability of the products to retain smooth seams, resist wrinkles and retain sharp, uniform creases. Furthermore, within the same process and material, performance will vary to some degree. The fact that such variations exist and that most Wash and wear products are not the ideal has created a need for a means to uniformly evaluate the wash and wear performance of such products. Lack of suitable means for such evaluation has created some disagreement in the clothing industry as to what constitutes a true wash and wear garment and has made quality control difiicult.

Hereafter in this specification, the term wash and wear performance or simply performance will be used in a somewhat limited sense as it is intended to indicate the ability of a material or product made from such material to retain sharp, uniform creases after being laundered 3,473,877 Patented Oct. 21, 1969 or washed. It is realized, of course, that the problem of sharp, uniform creases is only one aspect of the over-all problem which the broad concept of wash and wear is intended to surmount.

Some optical and mechanical methods for measuring the sharpness of creases and decorative darts have been developed. However, these do not possess the utility, versatility and wide applicability of the present invention. One such method uses the shadow cast by a light source at an oblique angle to the crease bump as a measure of the sharpness of the crease. This method necessitates extremely accurate positioning of the sample so that consistent readings are difficult. Furthermore, a dull crease in a heavy material would not be distinguishable from a very sharp crease in a relatively lighter material since both would cast the same shadow. Another method necessitates the cutting of a sample piece from the material under test. The drawbacks of the latter method are obvious.

The problems involved with creating a testing pro cedure and standard in any industry, are many. Any test procedure designed to evaluate performance quality must itself be capable of uniform application from one test to another and from one time to another. In general, the more basic a testing apparatus or procedure is, the more likely it is that accurate performance comparisons will be made. In order to be worthwhile, a performance evaluation procedure and apparatus, must be such as to allow rapid and accurate testing. Since in many cases, it is desired to evaluate the permanency of a crease in a finished garment, it is necessary in the present case that the testing procedure and apparatus used be such that the garment is not destroyed or damaged in any way by testing.

The present invention has the favorable qualities desired in a testing apparatus and procedure. One feature of the present invention is that tests of performance can be made rapidly on almost any sort of finished garment. Another feature is that the present invention is adaptable to performance testing of a wide range of materials including textiles and non-Wovens. The present invention is an improvement over present methods which rely heavily on operator expertise in handling and comparison and which in many cases necessitate partial destruction of the subject.

In view of the above, it is an object of the present in vention to provide an improved means for evaluating the sharpness of a crease in a material.

A further object is to provide an apparatus and method for rapidly evaluating the Wash and wear performance of a material.

Another object is to provide an apparatus for evaluating the sharpness and durability of a crease in a finished garment without destroying or damaging the garment.

In accordance with one aspect of the present invention, the foregoing and other objects are accomplished by projecting an image onto a crease and viewing the image by suitable means.

For a more complete understanding of the present invention, reference should be made to the drawings where- FIGURE 1 is a cut-away view of an apparatus constructed in accordance with the principles of the present invention.

FIGURE 2 is a schematic representation of the apparatus in FIGURE 1 in cross section showing a mounted sample.

FIGURE 3 is a top view of comparator means.

FIGURE 4 is a section through the A-A plane of FIGURE 1; and

FIGURE 5 is a schematic representation of an alternate embodiment of the principles of the invention.

The foregoing and other aspects of the present invention will be discussed more fully in the following paragraphs wherein specific examples of application of the principles of this invention are described.

FIGURE 1 shows one embodiment of an apparatus constructed in accordance with the principles of the present invention. An optical system is enclosed in a tubular body portion 1 supported at one end by support means 2.

A light source 4 is mounted at one end of the tubular portion. The light source emits a beam of light sufficiently bright to cast a well defined shadow. Projection lens means 4a are positioned to intercept the beam emitted by the light source. An opaque shadow casting means 4b is positioned between the light source and the lens means. The proper positioning of this opaque means which will be referred to hereinafter as the reticle is Well known. The reticle can be of any shape. However, most practically the reticle is typically a thin hair or wire which intercepts the beam of light emitted from the light source at a right angle. The image path of the reticle is shown graphically in FIGURE 1 as line 8.

A first reflecting means 6 is positioned in the path of the projected image 8. The reflecting means is carried by a suitable mount within the tubular portion. Means 6 receives the light emitted by light source 4, and reflects it through an opening 3, the opening being defined by the wall of the tubular portion.

When a performance evaluation test is to be made, a fabric material sample 20, represented in FIGURE 1 by a phantom line, is positioned on the tubular portion as shown in FIGURE 2. A portion of the sample lies above the opening and when properly positioned, the sample lies with the length of the crease lying along the length of the tubular portion.

In this specification, the concave contour of the crease will be termed the inside of the crease and the convex contour will be termed the outside of the crease. The shadow image may be projected on either the inside contour or the outside contour of the crease. The principles of the present invention concern generally the evaluation of the sharpness of a crease in a flexible material. A crease is imparted to a material for reasons of appearance as a general rule and not as a functional expedient. Since heaviness of the subject material is a variable, the evaluation of the crease from the inside serves to provide a more reliable indicia of the performance. The thickness of the material then is elfectively cancelled out as a variable and the sharper inner contour is viewed.

Returning to the example of FIGURE 1, the reticle is a cross-hair and casts a line shadow at an oblique angle across the fabric so that the shadow lies on the surface of the fabric generally perpendicular to the line of the apex of the crease in the sample When the sample is located above the opening. This straight line shadow is received by means 7, which is positioned at an angle of 45 to the plane normal to the line formed by the apex of the crease, as a broken line image which generally represents the shape of the crease as it might be viewed in cross section. Near means 7 within the optics tube is an enlarging lens 9 which focuses (or relays) an image of the broken line shadow. This broken line image is received by means 10 and is viewed through an eyepiece 11.

A comparator slide 12 such as the one shown in FIG- URE 3 can be placed in the line of vision to assist in the evaluation comparison. This slide is basically a transparent, flat piece which hasprinted or inscribed on it, various broken line representations 12b. The slide may be moved so that these representations pass in coincidence with the broken line image cast on the plate 11a by lens 9 until one of the characters coincides with the shadow. Both the image of the broken line shadow and the superimposed comparator slide are viewed through the eyepiece. These representations or characters are numbered and the crease is evaluated by assigning the number to the crease which corresponds to the representation which best fits the shadow cast. This means or comparison is, of course, quite elementary. There are electronic devices known in the art which can be utilized to assist in the comparison of the crease under test with certain standards. Basically there should be a means of viewing the projected image and comparing what is viewed with a standard. The comparison could range from the observation of an untrained eye as shown above to a complex electronic feedback system.

The present invention is adapted to the performance evaluation of fabric creases without destroying or damaging the subject material in any way. It can be readily seen that many types of mounting devices can be used so that a crease located in almost any part of a garment can be evaluated by this apparatus without disturbing the garment construction. This feature allows ready evaluation of not only the basic fabric, but also of individual finished garments of a wide variety. By reason of the physical nature of the optical system the present invention is very valuable as a means of quality control due to the fact that exactly the same thing is being done each time to the subject material.

FIGURE 4 is a section taken through the plane AA of the tubular portion 1 of FIGURE 1. This section shows a detail in cross section of the crease aligning means indicated generally by 13. The aligner in this embodiment consists of a bar which runs substantially the length of the tubular portion and which is centered about the orifice 3. Arm 14 is pivoted at pivot point 15 and engages the bar 16 which is free to ride up and down within the slot 15b. The aligner and portions of the associated mechanism are shown in FIGURE 1. This aligning mechanism assures that the crease of the sample will be centered about the orifice 3. By referring to FIGURE 4, which illustrates the slot 15b centered on the aperture, the effect of the bar should become readily apparent. The aligning bar also has the feature that it allows the garment to be naturally drapped on the tube when the bar is actuated two or three times to overcome tensions set up in the fabric when the garment is first slipped on the tube.

The shape and size of the tubular portion, since it serves as a means of mounting the sample, is a variable. However, these are readily standardized. The circular shape has proved to be quite practical and a diameter of about 3 inches is large enough to readily house the optical system. The coefficient of friction of the mounting means will also be a variable, however, this can be minimized by making the surface friction of the tubular portion very low.

It has been found that a tubular portion may be used to house the optical system utilized according to the principles of the present invention; however, there may be times where it is necessary only to evaluate portions cut from a piece of fabric which portions would be all about the same size. In such a case, instead of the tubular housing portion, a more box-like apparatus could be used. Such an embodiment would entail all the essential features as set out previously. However, instead of the material draping around the outside of the tubular portion, the sample would lie fiat as shown in FIGURE 5. In this figure, the sample 20 is shown schematically in cross section for purposes of illustration. The only basic difference is in the shape of the housing and the sample would be placed above an orifice in the housing and evaluated by a method similar to the one hereinbefore described. The FIGURE 5 shows the sample draped inside-out so that here the outside of the crease is being viewed. In both this embodiment and that of FIGURE 1, either the inside or the outside portion may provide the basis of comparison.

Again referring to FIGURE 1, the optical system utilizes a mirror 10 and a light collecting means 11. It can be readily seen that mirror 10 is used simply to make viewing more comfortable as it allows viewing from a top position. Many types of viewing systems are known and any of these may be utilized.

In FIGURE 1, the image viewed is an exact representation of the crease as it would appear in profile, the means 7 is at a 45 angle to the crease and so at an angle of 45 to the centerline 8 of the optical system. To carry this true representation of the viewing means, means 10 is also at a angle to the this same centerline. Various other angles could be utilized; however, the angle should be consistent if test results are to be consistent. In FIG- URE 1, mirror 6 is at a 22 /2" angle to the crease line. The beam of light is directed parallel to the crease line.

The various light reflecting and receiving means can be of any of the various suitable materials. They could be, for example, a common silvered glass mirror or a highly polished metal surface. The means must be suitable to receive and reflect the light beam so that the path of the reticle image is properly directed.

For an example of a typical test run, a trouser and the apparatus of FIGURE 1 will be used for purposes of illustration. The trouser leg would be slipped over the tubular portion 1 with either crease generally centered along the top of the tube. The aligning bar would then be actuated and would urge the leg portion upward and the weight of the garment would cause the garment to rest on the bar at the apex of the crease which is generally triangular in cross section. The bar would then be lowered. The source of illumination would then be turned on. In practice, the light source could remain on While various tests were made. Viewing would be through means 11 which consists of focusing lenses. The image for example, would be of a horizontally positioned hairline reticle located between the projection lens means and the source of illumination 4. The light and lenses cast a sharp line image which is reflected up onto the inside of the crease. The image is cast at right angles to the line formed by the apex of the crease. This image viewed through two mirrors at angles to each other and at 45 to the plane normal to the line of the apex of the crease and the plate 11a would be seen through the viewing means as a true representation of the pointed cross section shape of the crease.

The operator would then place the comparator 12 in the line of the light beam. The comparator is a glass plate having various angular forms etched thereon. The operator would determine which angle best coincided with the projected image of the crease. The crease would then be assigned a value corresponding to the angle giving coincidence.

Electronic means could be used to replace the operators visual comparison. A feedback system would register the best comparison with the image on a system of light sensitive comparators. The operator could move the trouser so that another portion of the crease would be above the opening and similarly compare the cross-section representation. By this means, comparisons can be made which reflect the degree of uniformity of the crease along its length.

The foregoing could utilize a collimating lens and a reticle located in the colliminated light beam. However, this is only one of the various optical means by which a suitable shadow may be cast. Many variations of the shadow casting means might be used, for example, locating the reticle in the focus of a lens system. The system must cast a well defined image. In the example, a straight hairline image was projected. It would be obvious that any contour of light and shadow or of various colors or shades could be utilized.

Although the present invention has been described with reference to specific apparatus, it will be appreciated by a person skilled in the art that a wide variety of changes mary be made without departing from the scope of this invention. For example, certain features of the apparatus may be used independently of others and equivalents may be substituted for the apparatus and method steps, all within the spirit and scope of the invention as defined in the appended claims.

We claim:

1. An apparatus for evaluating sharpness of a crease in a flexible material, comprising in combination: a hollow tube forming a rigid mounting surface and a portion of the tube defining an opening in the surface of the tube; means attached to the apparatus for positioning the material such that the material is disposed with a part of the crease centered over the opening, said means including means for lifting the material evenly along at least the portion of its length disposed above said opening; light beam generating means located at one end of the tube; means located in the path of the light beam for casting a line image; means located in the path of the light beam for directing the line image through the opening and at an angle to the plane normal to the line of the crease so as to cast an oblique shadow on the surface of the material; and means for viewing the shadow.

2. The apparatus of claim 1 wherein the lifting means includes a bar located within a slot defined by the tube and running generally along the length of the tube and means for raising the bar against the material to properly align the crease.

3. The apparatus of claim 1 including means for comparing the shadow image with a known standard.

References Cited UNITED STATES PATENTS 2,196,922 4/1940 Hybarger. 2,867,149 1/1959 Goddard. 3,022,578 2/1962 Seibel. 3,314,328 4/1963 Boettcher.

RONALD I. WIBERT, Primary Examiner T. R. MOHR, Assistant Examiner US. Cl. XR. 3346; 356- 

